If you are trying to download a legitimate copy of macOS and is stuck on Connecting to the Mac App Store, it is more than likely that you are attempting to do this from a Windows PC which will not have the App Store. You would need access to a desktop or laptop Mac.
Connecting to the Mac App Store..
To use the Mac App Store, you need Mac OS 10.6.6 or greater. For more
information, please click here.
Sadly, if you do get access to a desktop or laptop Mac or even a Hackintosh or HackBook, having Mac OS 10.6.6, Mac OS 10.6.7 or Mac OS 10.6.8 may not give you access. If that is the case with you, head on over the Gixxer PC where you can download macOS from Apple’s servers with a Windows PC.